The purpose of this project is to discover whether mapping of lymph nodes around gastric cancer identifies the sentinel lymph node(s) and accurately predicts the presence or absence of cancer in other lymph nodes around a gastric cancer. We are interested in determining whether this relatively simple methodology is reliable and applicable in a wide variety of practice settings and so have sent data sheets and instructions to all board certified surgeons in the State of Connecticut. Additional mailings were sent to 284 doctors in April of 1997 and again in July of 1997. This study used the CDMAS facilities and consulted with the Systems Manager.